Renesas RL78 Series User Manual page 417

RL78/G1D
13.3.16 Registers controlling port functions of serial input/output pins
Using the serial array unit requires setting of the registers that control the port functions
multiplexed on the target channel (port mode register (PMxx), port register (Pxx), port input mode register (PIMxx), port
output mode register (POMxx), port mode control register (PMCxx)).
For details, see 5.3.1 Port mode registers (PMxx), 5.3.2 Port registers (Pxx), 5.3.4 Port input mode registers
(PIMxx), 5.3.5 Port output mode registers (POMxx), and 5.3.6 Port mode control registers (PMCxx).
Specifically, using a port pin with a multiplexed serial data or serial clock output function (e.g. P02/ANI17/TXD1) for
serial data or serial clock output, requires setting the corresponding bits in the port mode control register (PMCxx) and port
mode register (PMxx) to 0, and the corresponding bit in the port register (Pxx) to 1.
When using the port pin in N-ch open-drain output (V
mode register (POMxx) to 1. When connecting an external device operating on a different potential (1.8 V or 2.5 V), see
5.4.5 Handling different potential (1.8 V, 2.5 V) by using I/O buffers.
Example When P02/ANI17/TxD1 is to be used for serial data output
Set the PMC02 bit of port mode control register 0 to 0.
Set the PM02 bit of port mode register 0 to 0.
Set the P02 bit of port register 0 to 1.
Specifically, using a port pin with a multiplexed serial data or serial clock input function (e.g. P03/ANI16/RxD1) for serial
data or serial clock input, requires setting the corresponding bit in the port mode register (PMxx) to 1, and the
corresponding bit in the port mode control register (PMCxx) to 0. In this case, the corresponding bit in the port register
(Pxx) can be set to 0 or 1.
When the TTL input buffer is selected, set the corresponding bit in the port input mode register (PIMxx) to 1. When
connecting an external device operating on a different potential (1.8 V or 2.5 V), see 5.4.5 Handling different potential
(1.8 V, 2.5 V) by using I/O buffers.
Example When P03/ANI16/RxD1 is to be used for serial data input
Set the PMC03 bit of port mode control register 0 to 0.
Set the PM03 bit of port mode register 0 to 1.
Set the P03 bit of port register 0 to 0 or 1.
R01UH0515EJ0120 Rev.1.20
Dec 16, 2016
CHAPTER 13 SERIAL ARRAY UNIT
tolerance) mode, set the corresponding bit in the port output
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